Managed to get in contact with "Telstra Platinum", apparently the fee will be waived this time as I managed to convince the first line tech support that a routing issue is not related to my computer or setup, therefore I don't require "technical support" with my equipment.
However, no luck there either upon reaching Platinum... I was simply told "the network is set up that way, there isn't anything we can do". So the network is set up to route packets bound for Japan that originate on the east coast of Australia, all the way across to Perth and then through Singapore/Hong Kong? Rather than route them out through Sydney straight to Japan? I've been testing this several times a day for the past week or more, to make sure it wasn't just a temporary routing issue, but I'm still getting the long paths rather than routing out the logical route through Sydney.
Starting to wish I hadn't switched to Telstra, as up until 2 weeks ago this wasn't an issue for me with my other provider... I was routing correctly out of Sydney across to Japan.
Iain do you know how I can get in contact with someone who will actually "run some tests and check the routing" as you have suggested? I've been having no luck so far - they either don't understand or they tell me there is nothing that can be done, without actually testing anything or looking at a traceroute.